The present invention relates to a new and improved construction of an electronic enciphering- and deciphering apparatus in the form of a pocket calculator, comprising an input device for the entering of the characters to be processed, a control device for the entering of control commands determining the mode of operation or function of the apparatus, an output device for the display of the information, and a power source for powering the apparatus.
It is preferable that cipher equipment for enciphering and deciphering of information should provide, to the extent possible, a visual indication of both the entered (primary) text and the processed (secondary) text.
In Swiss Patent No. 336,210 there is disclosed, for instance, a mechanically operating pocket apparatus for the enciphering and deciphering of characters, wherein both the non-processed and processed characters are visible. Yet, the use of this apparatus is cumbersome since the printed text to be processed must be enciphered and deciphered, character-for-character by means of the apparatus.